/* ============================================================
   Calc Web App — /may-tinh/ trang chính
   Modes tabs + sub-tabs + keypad + memory + history
   ============================================================ */

.calc-app {
    --calc-app-bg: var(--vjol-color-bg);
    --calc-app-border: var(--vjol-color-border);
    --calc-app-display-bg: #1e293b;
    --calc-app-display-text: #f8fafc;
    --calc-app-display-muted: #94a3b8;
    --calc-app-key-bg: var(--vjol-color-bg);
    --calc-app-key-border: var(--vjol-color-border);
    --calc-app-key-num-bg: #f8fafc;
    --calc-app-key-op-bg: #eff6ff;
    --calc-app-key-op-text: var(--vjol-color-primary);
    --calc-app-key-equal-bg: var(--vjol-color-primary);
    --calc-app-key-clear-bg: #dc2626;

    max-width: 720px;
    margin: 0 auto var(--vjol-space-12);
    background: var(--calc-app-bg);
    border: 1px solid var(--calc-app-border);
    border-radius: var(--vjol-radius-lg);
    overflow: hidden;
    box-shadow: var(--vjol-shadow-sm);
}

/* ---------- Title bar ---------- */

.calc-app__topbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--vjol-space-4) var(--vjol-space-5);
    border-bottom: 1px solid var(--calc-app-border);
}

.calc-app__title {
    font-size: var(--vjol-fs-lg);
    font-weight: var(--vjol-fw-semibold);
    color: var(--vjol-color-heading);
}

/* RAD/ĐỘ toggle */
.calc-app__angle {
    display: inline-flex;
    align-items: center;
    gap: var(--vjol-space-2);
    cursor: pointer;
    user-select: none;
}
.calc-app__angle-label {
    font-size: var(--vjol-fs-sm);
    color: var(--vjol-color-text-muted);
    font-weight: var(--vjol-fw-medium);
}
.calc-app__angle-input { display: none; }
.calc-app__angle-track {
    width: 44px;
    height: 24px;
    border-radius: var(--vjol-radius-full);
    background: var(--vjol-color-border);
    position: relative;
    transition: background-color var(--vjol-duration-fast) var(--vjol-ease-out);
}
.calc-app__angle-thumb {
    position: absolute;
    top: 2px;
    left: 2px;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: #fff;
    box-shadow: 0 1px 3px rgb(0 0 0 / 0.2);
    transition: transform var(--vjol-duration-fast) var(--vjol-ease-out);
}
.calc-app__angle-input:checked ~ .calc-app__angle-track {
    background: var(--vjol-color-primary);
}
.calc-app__angle-input:checked ~ .calc-app__angle-track .calc-app__angle-thumb {
    transform: translateX(20px);
}
.calc-app__angle-input:checked ~ [data-angle-on] { color: var(--vjol-color-primary); font-weight: var(--vjol-fw-semibold); }
.calc-app__angle-input:not(:checked) ~ [data-angle-off] { color: var(--vjol-color-primary); font-weight: var(--vjol-fw-semibold); }
.calc-app__angle-input:focus-visible ~ .calc-app__angle-track {
    outline: 2px solid var(--vjol-color-focus);
    outline-offset: 2px;
}

/* ---------- Display ---------- */

.calc-app__display {
    background: var(--calc-app-display-bg);
    color: var(--calc-app-display-text);
    padding: var(--vjol-space-6) var(--vjol-space-5);
    min-height: 140px;
    position: relative;
    text-align: right;
    font-family: 'JetBrains Mono', ui-monospace, monospace;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    word-break: break-all;
}

.calc-app__copy {
    position: absolute;
    top: var(--vjol-space-3);
    right: var(--vjol-space-3);
    width: 32px;
    height: 32px;
    background: rgb(255 255 255 / 0.08);
    color: var(--calc-app-display-muted);
    border-radius: var(--vjol-radius-sm);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: background-color var(--vjol-duration-fast) var(--vjol-ease-out),
                color var(--vjol-duration-fast) var(--vjol-ease-out);
}
.calc-app__copy:hover { background: rgb(255 255 255 / 0.15); color: #fff; }
.calc-app__copy.is-copied { background: var(--vjol-c-success); color: #fff; }

.calc-app__expr {
    font-size: var(--vjol-fs-base);
    color: var(--calc-app-display-muted);
    min-height: 1.4em;
    margin-bottom: var(--vjol-space-2);
}

.calc-app__result {
    font-size: clamp(var(--vjol-fs-2xl), 5vw, 2.5rem);
    font-weight: var(--vjol-fw-bold);
    line-height: 1;
}

/* ---------- Sub-tabs ---------- */

.calc-app__subtabs {
    display: flex;
    border-bottom: 1px solid var(--calc-app-border);
}

.calc-app__subtab {
    flex: 1;
    padding: var(--vjol-space-4) var(--vjol-space-2);
    border: 0;
    background: transparent;
    color: var(--vjol-color-text-muted);
    font-size: var(--vjol-fs-base);
    font-weight: var(--vjol-fw-medium);
    cursor: pointer;
    border-bottom: 2px solid transparent;
    transition: color var(--vjol-duration-fast) var(--vjol-ease-out),
                border-color var(--vjol-duration-fast) var(--vjol-ease-out);
}
.calc-app__subtab:hover { color: var(--vjol-color-heading); }
.calc-app__subtab.is-active {
    color: var(--vjol-color-primary);
    border-bottom-color: var(--vjol-color-primary);
    font-weight: var(--vjol-fw-semibold);
}

/* ---------- Memory row ---------- */

.calc-app__memory {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: var(--vjol-space-2);
    padding: var(--vjol-space-4) var(--vjol-space-5) 0;
}

.calc-app__mem {
    padding: var(--vjol-space-2) var(--vjol-space-1);
    background: var(--calc-app-bg);
    border: 1px solid var(--calc-app-border);
    border-radius: var(--vjol-radius-md);
    color: var(--vjol-color-text);
    font-size: var(--vjol-fs-sm);
    font-weight: var(--vjol-fw-medium);
    cursor: pointer;
    transition: background-color var(--vjol-duration-fast) var(--vjol-ease-out);
}
.calc-app__mem:hover { background: var(--vjol-color-surface); }
.calc-app__mem.is-active { background: var(--vjol-color-primary-soft); color: var(--vjol-color-primary); border-color: var(--vjol-color-primary); }

/* ---------- Keypad ---------- */

.calc-app__keys {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--vjol-space-2);
    padding: var(--vjol-space-4) var(--vjol-space-5);
}

.calc-app__keys[hidden] { display: none; }

.calc-app__key {
    padding: var(--vjol-space-4) var(--vjol-space-2);
    background: var(--calc-app-key-bg);
    border: 1px solid var(--calc-app-key-border);
    border-radius: var(--vjol-radius-md);
    color: var(--vjol-color-text);
    font-size: var(--vjol-fs-lg);
    font-weight: var(--vjol-fw-medium);
    cursor: pointer;
    transition: background-color var(--vjol-duration-fast) var(--vjol-ease-out),
                transform var(--vjol-duration-fast) var(--vjol-ease-out);
    min-height: 52px;
}
.calc-app__key:hover { background: var(--vjol-color-surface); }
.calc-app__key:active { transform: scale(0.96); }
.calc-app__key:focus-visible {
    outline: 2px solid var(--vjol-color-focus);
    outline-offset: 2px;
    z-index: 1;
}

.calc-app__key--num {
    background: var(--calc-app-key-num-bg);
    font-size: var(--vjol-fs-xl);
    font-weight: var(--vjol-fw-bold);
}
.calc-app__key--num:hover { background: var(--vjol-color-surface-2); }

.calc-app__key--op {
    background: var(--calc-app-key-op-bg);
    color: var(--calc-app-key-op-text);
    font-size: var(--vjol-fs-xl);
}
.calc-app__key--op:hover { background: var(--vjol-color-primary-soft); }

.calc-app__key--equal {
    background: var(--calc-app-key-equal-bg);
    color: #fff;
    border-color: var(--calc-app-key-equal-bg);
    font-size: var(--vjol-fs-xl);
}
.calc-app__key--equal:hover { background: var(--vjol-color-primary-hover); }

.calc-app__key--clear {
    background: var(--calc-app-key-clear-bg);
    color: #fff;
    border-color: var(--calc-app-key-clear-bg);
}
.calc-app__key--clear:hover { background: #b91c1c; }

/* ---------- Placeholder (Nâng cao / Casio coming soon) ---------- */

.calc-app__placeholder {
    padding: var(--vjol-space-12) var(--vjol-space-5);
    text-align: center;
    color: var(--vjol-color-text-muted);
}
.calc-app__placeholder h3 {
    margin: 0 0 var(--vjol-space-3);
    color: var(--vjol-color-heading);
}
.calc-app__placeholder p { margin-block: 0 var(--vjol-space-3); }
.calc-app__placeholder a {
    color: var(--vjol-color-primary);
    text-decoration: none;
    font-weight: var(--vjol-fw-medium);
}
.calc-app__placeholder a:hover { text-decoration: underline; }

.calc-app__keys--placeholder { display: block; padding: 0; }

/* ---------- Hint ---------- */

.calc-app__hint {
    padding: 0 var(--vjol-space-5) var(--vjol-space-4);
    text-align: center;
    color: var(--vjol-color-text-muted);
    font-size: var(--vjol-fs-sm);
    margin: 0;
}
.calc-app__hint kbd {
    display: inline-block;
    padding: 2px 6px;
    background: var(--vjol-color-surface);
    border: 1px solid var(--calc-app-border);
    border-radius: var(--vjol-radius-sm);
    font-family: 'JetBrains Mono', ui-monospace, monospace;
    font-size: 0.85em;
    margin: 0 2px;
}

/* ---------- History ---------- */

.calc-app__history {
    border-top: 1px solid var(--calc-app-border);
    padding: var(--vjol-space-4) var(--vjol-space-5);
}
.calc-app__history[hidden] { display: none; }

.calc-app__history-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--vjol-space-3);
}

.calc-app__history-title {
    margin: 0;
    font-size: var(--vjol-fs-base);
    font-weight: var(--vjol-fw-semibold);
    color: var(--vjol-color-heading);
}

.calc-app__history-clear {
    background: transparent;
    border: 0;
    color: var(--vjol-c-danger);
    cursor: pointer;
    font-size: var(--vjol-fs-sm);
    font-weight: var(--vjol-fw-medium);
    padding: 4px 8px;
    border-radius: var(--vjol-radius-sm);
}
.calc-app__history-clear:hover { background: rgb(220 38 38 / 0.08); }

.calc-app__history-list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: var(--vjol-space-1);
    max-height: 280px;
    overflow-y: auto;
    font-family: 'JetBrains Mono', ui-monospace, monospace;
    font-size: var(--vjol-fs-sm);
}
.calc-app__history-item {
    padding: var(--vjol-space-2) var(--vjol-space-3);
    background: var(--vjol-color-surface);
    border-radius: var(--vjol-radius-sm);
    cursor: pointer;
    transition: background-color var(--vjol-duration-fast) var(--vjol-ease-out);
}
.calc-app__history-item:hover { background: var(--vjol-color-surface-2); }
.calc-app__history-expr { color: var(--vjol-color-text-muted); }
.calc-app__history-result { color: var(--vjol-color-heading); font-weight: var(--vjol-fw-semibold); }

/* ---------- Responsive ---------- */

@media (max-width: 640px) {
    .calc-app__memory { grid-template-columns: repeat(3, 1fr); }
    .calc-app__keys { gap: 6px; padding: var(--vjol-space-3); }
    .calc-app__key { font-size: var(--vjol-fs-base); padding: var(--vjol-space-3) var(--vjol-space-1); min-height: 48px; }
    .calc-app__key--num, .calc-app__key--op, .calc-app__key--equal { font-size: var(--vjol-fs-lg); }
    .calc-app__topbar { padding: var(--vjol-space-3) var(--vjol-space-4); }
    .calc-app__display { padding: var(--vjol-space-4); min-height: 110px; }
}